Force-sensing processing method of a touchpad

ABSTRACT

A force sensing processing method of a touchpad is provided. The comparison values obtained by subtracting the force induction quantities of different frames are used to determine whether the achievement conditions are met. If it is met, a processing step is executed to respond the event to be triggered by the changing trend of the user&#39;s force. When the force changes rapidly and the force sensing amount cannot be quickly returned to the originally set trigger threshold value, the force changing trend detected by the comparison values are be used to provide the processing steps in real time, so as to improve the user experience.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims priority under 35 U.S.C. 119from Taiwan Patent Application No. 111129613 filed on Aug. 5, 2022,which is hereby specifically incorporated herein by this referencethereto.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a touchpad, especially to a touchpadwith a force-sensing function.

2. Description of the Prior Arts

With reference to FIGS. 6 and 7 , a conventional touchpad in accordancewith the prior art comprises a substrate 10, a force-sensing layer 11, aspacer layer 12, a touch-sensing layer 13 and a protective layer 14. Theforce-sensing layer 11 is mounted on the substrate 10. The spacer layer12 is mounted on the force-sensing layer 11. The touch-sensing layer 13is mounted on the spacer layer 12. The protective layer 14 is mounted onthe touch-sensing layer 13. The spacer layer 12 has multiple deformationunits 121 disposed separately therein. When the user's finger 20 appliesdownward pressure on the protective layer 14, the deformation units 121in the spacer layer 12 generate different amounts of deformation basedon the magnitude of the applied force and the distance from the point ofthe force application. The varying deformation amounts of thedeformation units 12 cause the distance between the touch-sensing layer13 and the force-sensing layer 11 at different positions to change. As aresult, different force-sensing values are generated in theforce-sensing layer 11 based on the magnitude of the force applied. Themagnitude of the force-sensing values is used to determine the magnitudeof the force applied by the user. When the user releases the appliedforce, the deformation units 121 gradually recover their shape due tothe elasticity as they no longer experience external force. This leadsto a gradual restoration of the distance between the touch-sensing layer13 and the force-sensing layer 11 to an unloaded state, resulting in agradual return of the force-sensing values to their initial state.

When the user performs rapid clicks, the user's finger 20 quicklychanges the applied force within a very short period of time, resultingin a pattern of applying force, release, applying force, release, and soon. However, the elastic recovery of the spacer layer 12 requires acertain amount of time. In the case of rapid switching between forceapplication and release, the spacer layer 12 cannot quickly recover to astate that accurately reflects the magnitude of the force duringrelease. As a result, it quickly deforms again due to the reapplicationof force, causing the detected force-sensing values to show variationsin magnitude. However, due to the insufficient rate of elastic recoveryof the spacer layer 12, the force-sensing values cannot decrease enoughto indicate a release event. As shown in FIG. 8 , when using a conditionwhere the force-sensing value is greater than 200 for triggering a clickevent and less than 100 for triggering a release event, it is apparentthat the user rapidly changes the applied force within a short period oftime, attempting to create a continuous clicking effect. However, asmentioned above, due to the slow elastic recovery rate of the spacerlayer 12, the force-sensing values have not decreased enough to triggera release event before the user applies force again, causing theforce-sensing values to increase. Therefore, although the user performscontinuous clicking actions, the conventional touchpad fails to reflectthe continuous clicking events, resulting in a poor user experience.

To overcome the shortcomings, the present invention provides aforce-sensing processing method for a touchpad to mitigate or to obviatethe aforementioned problems.

SUMMARY OF THE INVENTION

To achieve the objectives, the present invention provides aforce-sensing processing method for a touchpad to effectively respond tocontinuous click events.

The present invention provides a force-sensing processing methodcomprising steps of: a force-sensing processing method for a touchpadcomprising steps of: a. collecting force-sensing values of a touchobject in different frames; b. obtaining a comparison value bycalculating the force-sensing values collected in two of the frames; c.determining whether the comparison value meets a first achievementcondition; and d. executing a first processing if the comparison valuemeets a first achievement condition.

The advantage of the present invention lies in obtaining the user'sforce trend by comparing the force-sensing values in different frames.Based on the force changing trend, the present invention determineswhether the conditions are met and performs corresponding processing. Byconsidering the relative values of force variation rather than solelyrelying on absolute values, the present invention effectively respondsthe relative force changes in the case of continuous clicking. Thisenables the touchpad to make real-time determinations and thus enhancesthe user experience.

Other objectives, advantages and novel features of the invention willbecome more apparent from the following detailed description when takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of a force-sensing processing method inaccordance with the present invention;

FIG. 2 is a timing diagram illustrating the frames at different timewhen the force-sensing processing method in FIG. 1 is operating;

FIG. 3 is a relationship chart illustrating the frames and theforce-sensing values when the force-sensing processing method in FIG. 1is operating;

FIG. 4 is a flow chart of another embodiment of a force-sensingprocessing method in accordance with the present invention;

FIG. 5 is a relationship chart illustrating the frames and theforce-sensing values when the force-sensing processing method in FIG. 4is operating;

FIG. 6 is a side view in a partial section of a conventional touchpad inaccordance with the prior art;

FIG. 7 is an operational side view in a partial section of theconventional touchpad in FIG. 6 ; and

FIG. 8 is a relationship chart illustrating the frames and theforce-sensing values when the conventional touchpad in FIG. 6 isoperated.

DETAILED DESCRIPTION OF THE EMBODIMENTS

With reference to FIG. 1 , a first embodiment of a force-sensingprocessing method in accordance with the present invention comprises thefollowing steps.

Collecting force-sensing values of a touch object on a touchpad indifferent frames (S10): With further reference to FIG. 2 , the touchpadsenses the force-sensing values generated by the touch object exertingforce on the touchpad. The touchpad collects the force-sensing values ata preset frame rate. Using the frame rate of 144 Hz as an example, theforce-sensing value is obtained once in an average of about 7microseconds (ms). Assuming the time T1 shown in FIG. 2 is an initialtime, the corresponding frame at the time T1 is the frame F1, thecorresponding frame at the time T2 is the frame F2, the correspondingframe at the time T3 is the frame F3, and the corresponding frame at thetime T4 is the frame F4, the frame corresponding to the time T5 is theframe F5, the frame corresponding to the time T6 is the frame F6, and soon. Then the force-sensing value of the frame F1 is obtained at the timeT1, the force-sensing value of the frame F2 is obtained at the time T2,etc. The touchpad saves the force-sensing values of the preset number ofthe frames. For example as shown in FIG. 2 , the touchpad saves theforce-sensing values of four frames, but it is not limited thereto. Whenthe force-sensing value of the frame F5 is obtained, the force-sensingvalues of the frames F2 to F5 are preserved and the force-sensing valuesof the frame F1 is abandoned.

Obtaining a comparison value (S20): The comparison value is asubtraction of the force-sensing values obtained in different frames. Inone embodiment, the force-sensing value of the n^(th) frame minus theforce-sensing value of the n−m^(th) frame to obtain the comparisonvalue. The “n” and “m” are positive integers, and n is larger than m.Since the comparison value is used to determine whether the changingtrend of the force-sensing values is increasing or decreasing, thechange of force-sensing values in adjacent frames may be misjudged dueto inadvertent operation. Thus, in one embodiment, m is larger or equalto 2. It means to determine the changing trend of the force-sensingvalues by comparing the force-sensing values separated by at least oneframe. As shown in FIG. 2 and using that m is equal to 2, the comparisonvalue is obtained by subtracting the force-sensing value of the frame F1from the force-sensing value of the frame F3, subtracting theforce-sensing value of the frame F2 from the force-sensing value of theframe F4, and so on. In one embodiment, it further determines thatwhether the amount of the frames of the collected force-sensing valuesis larger than m+1 in the step S10. If so, the step S20 is executed. Ifnot, the step S10 is kept executing.

Determining whether the comparison value meets a first achievementcondition (S30): Since the comparison value presents a changing trend ofthe force-sensing values, determining whether the comparison value meetsthe first achievement condition is to determine whether the changingtrend of the force-sensing values has reached a preset condition thatneeds to be adjusted. If the first achievement condition is met, a firstprocessing (S40) is executed so that the changing trend of the exertingforce by the touch object are responded in time. If the firstachievement condition is not met, the step S10 is executed.

In one embodiment, to determine when the comparison value meets thefirst achievement condition is to determine whether the comparison valueis less than a first threshold. The first threshold is a negative value.For example, the force-sensing value of the frame that occurred laterminus the force-sensing value of the frame that occurred earlier. Asshown in FIG. 2 , the force-sensing value of the frame F4 minus theforce-sensing value of the frame F2. If the comparison value is lessthan the first threshold, it means that the force-sensing value of thelater frame is less than the force-sensing value of the earlier frame,indicating that the change of the force-sensing value shows a decreasingtrend. Then when the decreasing trend reaches the preset condtion thatneeds to be adjusted, the first processing is still actuated because thecomparison value has met the first achievement condition. In this way,the change of the force applied by the user responds in time by thechanging trend of the force-sensing values, and the first processing isactuated.

In one embodiment, when it is determined that the comparison value isless than the first threshold in the n^(th) frame, the first processingrefers to lowering the force-sensing value of the n^(th) frame to apreset force-sensing value. The preset force-sensing value relates to adetermination standard of a releasing event. In one embodiment, thepreset force-sensing value is less than a releasing threshold. When theforce-sensing value is less than the release threshold, it is determinedthat the user decreases the applied force to actuate the release event.Therefore, the preset force-sensing value is less than the releasethreshold means that the adjusted force-sensing value can actuate therelease event. For the touchpad, the adjusted force-sensing value isrecognized as the current real force-sensing value and is used todetermine whether to trigger the release event. In another aspect, Whenthe touchpad transmits the force-sensing value information to theelectronic device, the touchpad recognizes the reduced force-sensingvalue as the current real force-sensing value and sends it to theelectronic device. The action or event to be triggered is furtherdetermined by the electronic device according to the reducedforce-sensing value.

For example, as shown in FIG. 3 , the force-sensing values detected bythe touchpad are drawn as an original force-sensing value line FVO. Theforce-sensing values after adjustment are drawn as a virtualforce-sensing value line FVA. The release threshold is 100. It can beclearly seen from FIG. 3 that the slope of the original force-sensingline FVO is relatively large, which means that the force applied by theuser changes quite rapidly. When the applied force changes rapidly, thespacer layer in the middle of the touchpad has no time to return to itsoriginal shape when the user releases the force, which causes theforce-sensing value to drop not fast enough. Therefore, it can be seenthat although the force-sensing line FVO quickly presents the situationof applying force→releasing→applying force→releasing . . . , it cannottrigger the release event. For example, the force-sensing value V1detected at the 72^(nd) frame is 260, which is not less than the releasethreshold value of 100, and the release event is not directly triggered.However, under the determination of step S30, it is considered that thecomparison value has met the first achievement condition at this time,and the first processing must be performed. That is, it is determined atthe 72^(nd) frame that the downward trend of the force-sensing value hasreached, and the release event should be triggered. Therefore, theforce-sensing value of the 72^(nd) frame is subjected to the firstprocessing, i.e. that the force-sensing value of the 72^(nd) frame isreduced to a preset force-sensing value VA1, which is 80 as shown inFIG. 3 . At this time, because the preset force-sensing value VA1 isless than the release threshold value 100, the release event istriggered. Furthermore, when it is determined in the n−1^(th) frame thatthe comparison value is not less than the first threshold, and in then^(th) frame it is determined that the comparison value is less than thefirst threshold, and in the n+1^(th) frame it is determined that thecomparison value is still less than the first threshold, theforce-sensing value in the n+1^(th) frame is adjusted based on the ratioof the force-sensing value in the n^(th) frame to the presetforce-sensing value. Specifically, the force-sensing value in the72^(nd) frame is still used as an example. At the 71^(st) frame, it isdetermined that the comparison value is not less than the firstthreshold, so the force-sensing value at the 71^(st) frame is notadjusted. However, at the 72^(nd) frame, it is determined that thecomparison value is less than the first threshold, and the force-sensingvalue V1 (260 as shown in FIG. 3 ) is lowered to the presetforce-sensing value VA1 (80 as shown in FIG. 3 ). At this time, the nextframe is the 73^(rd) frame, and it is still determined that thecomparison value is less than the first threshold, then theforce-sensing value V2 at the 73^(rd) frame (240 as shown in FIG. 3 ) isadjusted according to the ratio (260/80) of the force-sensing value V1(260) at the 72^(nd) frame to the preset force-sensing value VA1 (80),which becomes the adjusted force-sensing value VA2 (about 74). Byanalogy, the force-sensing values of subsequent frames are adjusteduntil the comparison value is no longer less than the first threshold.

With reference to FIG. 4 , a second embodiment of a force-sensingprocessing method in accordance with the present invention comprisessimilar steps to the first embodiment: collecting force-sensing valuesof a touch object on a touchpad in different frames (S10A), obtaining acomparison value (S20A), determining whether the comparison value meetsa first achievement condition (S31A), executing a first processing ifthe step S31A determines the comparison value meets a first achievementcondition (S41A), and further comprises following steps:

Determining whether the comparison value meets a second achievementcondition if the step S31A determines the comparison value does not meetthe first achievement condition (S32A): Since the comparison valuepresents a changing trend of the force-sensing values, determiningwhether the comparison value meets the second achievement condition whenthe comparison value does not meet the first achievement condition is todetermine whether the changing trend of the force-sensing values hasreached a preset condition that needs to be adjusted. If the secondachievement condition is met, a second processing (S42A) is executed torespond to the changing trend of the force-sensing values so that thechanges of the exerting force by the touch object are responded in time.If the second achievement condition is not met, the step S10A isexecuted.

In one embodiment, to determine when the comparison value meets thefirst achievement condition is to determine whether the comparison valueis less than a first threshold. The first threshold is a negative value.To determine when the comparison value meets the second achievementcondition is to determine whether the comparison value is larger than asecond threshold. The second threshold is a positive value. For example,the force-sensing value of the frame that occurred later minus theforce-sensing value of the frame that occurred earlier. As shown in FIG.2 , the force-sensing value of the frame F4 minus the force-sensingvalue of the frame F2. If the comparison value is less than the firstthreshold, it means that the force-sensing value of the later frame isless than the force-sensing value of the earlier frame, indicating thatthe change of the force-sensing value shows a decreasing trend. Thenwhen the decreasing trend reaches the preset condition that needs to beadjusted, the first processing is still actuated because the comparisonvalue has met the first achievement condition. In the same manner, Ifthe comparison value is larger than the second threshold, it means thatthe force-sensing value of the later frame is larger than theforce-sensing value of the earlier frame, indicating that the change ofthe force-sensing value shows an increasing trend. Then when theincreasing trend reaches the preset condition that needs to be adjusted,the second processing is actuated.

In one embodiment, when the comparison value is determined as less thanthe first threshold, the first processing means to determine that thetouch object triggers a release event. When the comparison value isdetermined as larger than the second threshold, the second processingmeans to determine that the touch object triggers a click event.

For example, as shown in FIG. 5 , the force-sensing values detected bythe touchpad are drawn as a force-sensing value line FV. The releasethreshold is preset as 125, and the click threshold is preset as 150.FIG. 5 also shows a first result line RO for determining whether totrigger a click event (Y1) or a release event (N) according to acomparison result of the force-sensing values with the release thresholdand the click threshold. FIG. 5 also shows a second result line RA fordetermining whether to trigger a click event (Y2) or a release event (N)according to the method described in the second embodiment of thepresent invention. Before the 100^(th) frame, the slope of theforce-sensing value line FV is small, which means that the force appliedby the user does not change very quickly. Therefore, the comparisonbetween the value of the force-sensing value itself and the releasethreshold and the click threshold is enough to determine whether totrigger the click event and the release event. Then the determination ofthe first result line RO or the determination of the second result lineRA are consistent. After about the 100^(th) frame, it can be seen thatthe slope of the force-sensing line FV becomes larger, which means thatthe force applied by the user changes quite rapidly. When the appliedforce changes rapidly, the spacer layer in the middle of the touchpadhas no time to return to its original shape when the user releases theforce, which causes the force-sensing value to drop not fast enough.Therefore, it can be seen that although the force-sensing line FVquickly presents the situation of applying force→releasing→applyingforce→releasing . . . , the force-sensing value is not less than therelease threshold and cannot trigger the release event. Then as shown bythe first result line RO, it continues to trigger the click event.However, after the above-mentioned first processing and secondprocessing are performed by the method of the second embodiment of thepresent invention, it is determined according to the changing trendwhether the increase or decrease of the force-sensing value is enough totrigger the click event or the release event. Then, it is presented as asecond result line RA, effectively triggering the click event or therelease event according to the changing trend of applied force.

In summary, the method as described utilizes the comparison values offorce-sensing values in different frames to obtain the changing trend ofthe applied force. Based on the changing trend of the applied force, themethod as described performs corresponding processing, such as adjustingforce-sensing value or triggering click or release events. By respondingto the desired effect of the user's current operation in real-timeaccording to the changing trend of the applied force, the method asdescribed effectively enhances user experience.

Moreover, in one embodiment, before executing the aforementioned stepS20 or S20A, it is first determined whether the force-sensing value ofthe frame collected in the step S10 or S10A is greater than a thirdthreshold. If the force-sensing value of the frame collected in the stepS10 or S10A is determined as greater than the third threshold, the stepS20 or S20A is executed to obtain the comparison value. That is to saywhen the force-sensing value has not yet reached the third threshold, itmeans that the applied force by the user has not triggered the clickevent yet. Thus, the changing trend of force application may have noreference value. Then there is no need to obtain the comparison valueand make subsequent determinations and processing.

Even though numerous characteristics and advantages of the presentinvention have been set forth in the foregoing description, togetherwith details of the structure and features of the invention, thedisclosure is illustrative only. Changes may be made in the details,especially in matters of shape, size, and arrangement of parts withinthe principles of the invention to the full extent indicated by thebroad general meaning of the terms in which the appended claims areexpressed.

What is claimed is:
 1. A force-sensing processing method for a touchpad comprising steps of: a. collecting force-sensing values corresponding to a touch object in different frames; b. obtaining a comparison value by calculating the force-sensing values collected in two of the frames; c. determining whether the comparison value meets a first achievement condition; and d. executing a first processing if the comparison value meets a first achievement condition.
 2. The force-sensing processing method for a touchpad as claimed in claim 1, wherein in the step b, the comparison value of n^(th) frame is obtained by subtracting a force-sensing value of n−m^(th) frame from a force-sensing value of n^(th) frame; n is a positive integer larger than m; and m is a positive integer larger than or equal to
 2. 3. The force-sensing processing method for a touchpad as claimed in claim 2, wherein in the step c, determining whether the comparison value meets the first achievement condition is to determine whether the comparison value is less than a first threshold; and the first threshold is a negative value.
 4. The force-sensing processing method for a touchpad as claimed in claim 3, wherein the first processing in the step d is to trigger a release event.
 5. The force-sensing processing method for a touchpad as claimed in claim 3, wherein the first processing in the step d is to adjust a force-sensing value of the n^(th) frame to a preset force-sensing value; and the present force-sensing value is used for a determination of a release event.
 6. The force-sensing processing method for a touchpad as claimed in claim 5, wherein when it is determined in the n−1^(th) frame that the comparison value is not less than the first threshold, in the n^(th) frame it is determined that the comparison value is less than the first threshold, and in the n+1^(th) frame it is determined that the comparison value is still less than the first threshold, the force-sensing value in the n+1^(th) frame is adjusted based on a ratio of the force-sensing value in the n^(th) frame to the preset force-sensing value.
 7. The force-sensing processing method for a touchpad as claimed in claim 1, wherein the step c also comprises a step of determining whether the comparison value meets a second achievement condition; and the step d also comprises a step of executing a second processing if the comparison value meets the second achievement condition.
 8. The force-sensing processing method for a touchpad as claimed in claim 2, wherein the step c also comprises a step of, determining whether the comparison value meets a second achievement condition; and the step d also comprises a step of: executing a second processing if the comparison value meets the second achievement condition.
 9. The force-sensing processing method for a touchpad as claimed in claim 3, wherein the step c also comprises a step of determining whether the comparison value meets a second achievement condition; and the step d also comprises a step of executing a second processing if the comparison value meets the second achievement condition.
 10. The force-sensing processing method for a touchpad as claimed in claim 6, wherein the step c also comprises a step of determining whether the comparison value meets a second achievement condition; and the step d also comprises a step of executing a second processing if the comparison value meets the second achievement condition.
 11. The force-sensing processing method for a touchpad as claimed in claim 8, wherein in the step c, determining whether the comparison value meets the second achievement condition is to determine whether the comparison value is larger than a second threshold; the second threshold is larger that the first threshold; and the second threshold is a positive value.
 12. The force-sensing processing method for a touchpad as claimed in claim 10, wherein in the step c, determining whether the comparison value meets the second achievement condition is to determine whether the comparison value is larger than a second threshold; the second threshold is larger that the first threshold; and the second threshold is a positive value.
 13. The force-sensing processing method for a touchpad as claimed in claim 7, wherein the second processing in the step d is to determine that the touch object triggers a click event.
 14. The force-sensing processing method for a touchpad as claimed in claim 9, wherein the second processing in the step d is to determine that the touch object triggers a click event.
 15. The force-sensing processing method for a touchpad as claimed in claim 11, wherein the second processing in the step d is to determine that the touch object triggers a click event.
 16. The force-sensing processing method for a touchpad as claimed in claim 12, wherein the second processing in the step d is to determine that the touch object triggers a click event.
 17. The force-sensing processing method for a touchpad as claimed in claim 2 further comprising a step a1 executing before the step b, wherein the step a1 comprises steps of: determining whether the force-sensing value of n^(th) frame is larger that a third threshold; if the force-sensing value of n^(th) frame is larger that a third threshold, executing the step b when the touch object triggers a click event; and executing the steps a and a1 if the force-sensing value of n^(th) frame is not larger that a third threshold.
 18. The force-sensing processing method for a touchpad as claimed in claim 6 further comprising a step a1 executing before the step b, wherein the step a1 comprises steps of: determining whether the force-sensing value of n^(th) frame is larger that a third threshold; if the force-sensing value of n^(th) frame is larger that a third threshold, executing the step b when the touch object triggers a click event; and executing the steps a and a1 if the force-sensing value of n^(th) frame is not larger that a third threshold.
 19. The force-sensing processing method for a touchpad as claimed in claim 2, wherein the step a further comprises steps of determining whether an amount of the frames of the collected force-sensing values is larger than m+1; executing the step b if the amount of the frames of the collected force-sensing values is larger than m+1; and executing the step a if the amount of the frames of the collected force-sensing values is not larger than m+1.
 20. The force-sensing processing method for a touchpad as claimed in claim 6, wherein the step a further comprises steps of determining whether an amount of the frames of the collected force-sensing values is larger than m+1; executing the step b if the amount of the frames of the collected force-sensing values is larger than m+1; and executing the step a if the amount of the frames of the collected force-sensing values is not larger than m+1. 